1. Field of the Invention
Embodiment of the present invention relate to a liquid crystal display (LCD) device, and more particularly, to an LCD device using various inversion systems and a driving method thereof.
2. Discussion of the Related Art
With the advance of various portable electronic devices such as mobile communication terminals, smart phones, tablet computers, notebook computers, etc., demand for flat panel display (FPD) devices applicable to the portable electronic devices is increasing. Liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission display (FED) devices, organic light emitting display devices, etc., are being actively researched as the FPD devices.
In such FPD devices, the LCD devices are being most widely commercialized at the present because the LCD devices are easily manufactured due to the advance of manufacturing technology, the drivability of a driver and a high-quality image, and
The LCD devices drive a liquid crystal panel in various inversion systems, for preventing a deterioration of liquid crystal and enhancing a display quality. As inversion systems, there are a frame inversion system, a line Inversion system, a column inversion system, a dot inversion system, a Z-inversion system, etc.
FIG. 1 depicts diagrams for describing a general line inversion system, and especially, illustrates a horizontal 1-line inversion system. FIG. 2 depicts diagrams for describing a general dot inversion system, and especially, illustrates a vertical 1-dot and horizontal 1-dot inversion system.
In the above-described inversion systems, as illustrated in FIG. 1, the line inversion system inverts polarities of data voltages (supplied to respective pixels) in units of a horizontal line, and inverts polarities of data voltages in units of a frame.
A portion (a) of FIG. 1 illustrates polarities of data voltages in a 2nth frame, and a portion (b) of FIG. 1 illustrates polarities of data voltages in a 2n+1st frame. In the horizontal 1-line inversion system, polarities of data voltages supplied to respective pixels are inverted in units of a horizontal line in one frame, and, polarities of data voltages of the same horizontal line are inverted in units of a frame.
In the above-described inversion systems, as illustrated in FIG. 2, the dot inversion system inverts polarities of data voltages (supplied to respective pixels) in units of a dot, and inverts polarities of data voltages in units of a frame.
A portion (a) of FIG. 2 illustrates polarities of data voltages in a 2nth frame, and a portion (b) of FIG. 2 illustrates polarities of data voltages in a 2n+1st frame. In the vertical 1-dot and horizontal 1-dot inversion system, polarities of data voltages supplied to respective pixels are inverted in units of adjacent pixels in one frame, and, a polarity of a data voltage of the same pixel is inverted in units of a frame.
In addition, the above-described inversion systems invert polarities of data voltages supplied to respective pixels in various types.
The above-described inversion systems of the related art invert polarities of dots in units of a frame, and do not change an inversion method.
The inversion systems of the related art invert a polarity of a horizontal 1 line in units of a frame (horizontal 1-line inversion system), invert a polarity of vertical 1 dot and horizontal 1 dot (vertical 1-dot and horizontal 1-dot inversion system), or invert polarities of all dots in units of a frame (frame inversion system).
In LCD devices using the above-described inversion system of the related art, as described above, since a polarity of a dot is inverted in units of a frame and an inversion method is not changed, the following problems occur.
First, a transmittance difference occurs even in the same dot according to polarities.
Second, a transmittance difference between adjacent dots is caused by a polarity difference, causing visual flickers.
Third, flickers occur heavily in a screen vulnerable to a specific inversion driving method.
In LCD devices using the related art inversion system, since a process differential of a liquid crystal panel occurs and driving voltages of liquid crystal differ, a capacitance differential occurs in the liquid crystal panel. In this instance, when positive and negative polarities of 1 dot differ in level, a transmittance difference occurs, causing visual flickers. Also, regardless of inversion systems (inversion driving systems), there is a screen vulnerable to flickers, and for this reason, there is a limitation in reducing flickers due to a panel differential by using one inversion system.